Marbles In A Bag
Get a color assortment of marbles (red, blue, green, swirls, etc.) and count the number of marbles for each color, then count the total number of marbles. Have your child practice writing the fraction for the part (# of marbles for a color) and whole (total marbles).
Once the numbers have been determined, relate the fractions to probability. The color with the most marbles will have a higher probability of being chosen out of the bag, than the color with the least marbles.
Try it out and see if you’re right.